A couple of efi wiring Q's

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Coastcard
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A couple of efi wiring Q's

Post by Coastcard »

Nearly completed my autobox and flapper install into my Land Rover. Have a couple of questions before I start cutting wires!

From the v. useful flapper diagram thread above, it says that the White/Red (on the flapper loom) goes to crank side of ignition switch (only live while turning engine over). Would this be what I would call the pre-relay side i.e the same as the gearbox inhibit (which links into the white/red crank wire from the ignition switch on the LR), or the 'full beans' side i.e. the wire to the starter solenoid. If the gearbox inhibit side, I assume it goes after the gearbox switch as there isn't much point firing the ecu if the gearbox is stopping everything else.

Secondly, I have a relay off the loom by the coil/afm with one red wire (pin 30/51) not connected and a spare spade on the negative with a 6.6k inline spade resistor. Should these two be paired up? There are 3 other wires on the relay, white, black and white/black.

Thanks in anticipation of hearing that V8 :D


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ChrisJC
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Post by ChrisJC »

I am not sure of the correct answer to your 1st question, but I do know that it doesn't matter. The white / red wire simply makes the fuel pump run whilst cranking, until it fires there isn't enough air flowing through the AFM to close the contacts in there to keep the fuel pump running.

Not sure of the colours, but for your second question, that relay connects the low tension side of the coil to the ECU. The signal comes in to the relay on white/black, not sure of the exit colour. And yes at some point it needs to go into the ECU loom. There's a debate about whether you need the inline resistor (I say you don't), but since you have it you might as well use it.
That relay is controlled by the overrun cutoff valve, so in fact you could just bypass it completely.

Not sure I've completely answered you, but hope that's some help!

Chris.
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Coastcard
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Post by Coastcard »

Thanks Chris,

Yes it does make sense thanks. Basically the white/red is what I would call a trigger wire, so not carrying 'full beans' (beans are on the purple fuel pump feed). So it would seem that I am OK, dare I say it correct, to wire on the trigger side of relay. If it fires the fuel pump, I will also put it in after the gearbox inhibit switch.

Many thanks.
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